Siltronic Ag

Martin Pickel

Reinhard Schauer

Friedrich Passek

Frank Laube

Epitaxially coated silicon wafers have a rounded and polished edge region and a region adjacent to the edge having a width of 3 mm on the front and rear sides, a surface roughness in edge region of 0.1-1.5 nm RMS relative to a spatial wavelength range of 10-80 &#x3bc;m, and a variation of surface roughness of 1-10%. The wafer edges, after polishing, are examined for defects and roughness at the edge and surrounding region. Silicon wafers having a surface roughness of less than 1 nm RMS are pretreated in single wafer epitaxy reactors, first in a hydrogen atmosphere at a flow rate of 1-100 slm and in a second step, an etching medium with a flow rate of 0.5-5 slm is conducted onto the edge region of the wafer by a gas distribution device. The wafer is then epitaxially coated.

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Burghausen, Germany

Martin Pickel